This is an F14 Tomcat
from VF-114, called the Flying Aardvarks, with engines on full power, without
afterburner, sitting on the catapult.

If you look real
close at the exhaust nozzles, you will see that they are at their smallest
position.
When the engine hits afterburner, the nozzles open to their
widest position.

At Oshkosh 1999,
I found another name for the exhaust nozzles is turkey feathers

I need your help!
I wish an F14 pilot would send me a story and photo's of his 00098620009862ALT="F-14 Tomcat Jet Figther Picture" HSPACE=10 VSPACE=10 BORDER=2 height=197 width=250 align=RIGHT>experience
on a carrier.
Send me e-mail at the bottom of this page.

Look at the structure standing up behind this F14
Tomcat.
This is a Jet Blast Deflector.
It is a part of the
deck which is lifted up with hydraulics and prevents the super high speed
super hot jet blast from blowing down the deck.
The JBD is water
cooled to prevent the extreme heat for the exhaust from melting its surface.

I used to sleep under the JBD of the left front
catapult.
Once we were past Hawaii we had flight ops almost continuously.
These aircraft were pumping out over 40,000 lbs. of thrust less than ten
feet above my head.
I could hear the hydraulic pump lifting the JBD
behind the Jet. The engines were turned up to full power for
a few seconds, then the catapult launched the aircraft off of the deck.
When the catapult shuttle hit the water brake at the end of the deck, the
entire ship would shake.

This wasn't launch an airplane and wait.
This was launch one airplane, then another, then another, non-stop, until
all of the squadrons were off the deck.
When it was time to sleep
you would think that this was an annoyance.
I can't believe it myself,
but it never bothered me.
I guess it was just a way of life.

I need your help to make this website grow.
If you have any stories or photo's of carrier life or carrier operation,
please send them to me at the bottom of this page.

8-16-00 Subject:
F-14 Exhaust Nozzles, jet blast deflector

Hi,My name is LCDR
Andy Loiselle.
Here is some information on exhaust nozzles.
They work on a basic principle of pressure being
inversely
proportional to velocity.
As velocity goes down, pressure goes up
and vice versa.
When the nozzle is open on deck, that is to
reduce residual thrust so people behind the jet are not blown over.
Once the throttles are brought off the idle stops, the nozzles begin to
"pucker" to increase the thrust.
When the nozzles pucker, it appears
that the hole at the end of the engine is getting smaller.
While
this
is true, this is not what generates additional thrust.
When the nozzle closes, there is a section midway through the nozzle that
closes
even smaller than the exit of the nozzle.
As the exhaust
gasses get constricted in the nozzle, the pressure goes up as the velocity
goes
down.
When the inside of the nozzle begins to expand again,
there is a very substantial pressure drop as the nozzle opens to the
athmosphere.
This allows a rapid increase in velocity as the exhaust
gasses exit the engine.

When afterburners
are operated, the nozzle does not have to generate as much of a pressure
differential due to the large amount of
pressure being generated
in the afterburner
section.
This is why the nozzle is gradually opened as the burners
stage.
DLC is direct lift control and is controlled by a thumbwheel
on the control stick.
It modulates the two inboard spoilers over
the wing in
order to modulate the amount of lift that the wing is
generating.
If you are getting high on your approach, you can extend
the spoilers and
maybe still get in the wires.
Because
the F-14 does not have ailerons, it rolls via differential horizontal stabilators
and the use of spoilers
on the down going wing.

Hope this helps.

Andy Loiselle

8-16-00Re: F-14
Exhaust Nozzles from the
webmaster

I was also
wondering if the exhaust nozzle will change its size according to altitude?

8-19-00Re: F-14 Exhaust
Nozzles

Hello Jeff, The exhaust nozzles
do not change size at anything less than military
(non-afterburner)
power, except at idle, regardless of altitude.
There is a
change
in nozzle programming for afterburners operation as altitude
increases.
At very high altitude, the nozzles may only open up 50%
or so at
full A/B, while they would be open about 95%or so
at sea level.
This is due
to the amount of thrust being
developed at the different altitudes. The
rated thrust of an engine is always quoted for sea level operation.
Military power at sea level may burn 10,000 pounds (1500 gallons/hour)
per
hour per engine, while at 35,000 feet, fuel burn would
be more like 4000
pounds/engine.
This means that there
is less pressure developed in the
afterburner section at high altitude,
so the nozzle does not open as much.